package chapter10.demo1;

import java.sql.*;
import java.util.Scanner;

public class Demo1 {
    public static void main(String[] args) throws SQLException {
        // 修改用户名和密码
        /**
         * 1.注册驱动
         * 2.获取连接
         * 3.创建表结构对象
         * 4.执行SQL对象
         * 5.操作返回结果
         * 6.关闭连接
         */
        Statement stmt = null;
        ResultSet rs = null;
        Connection conn = null;
        try {
            // 1.注册数据库的驱动
            Class.forName("com.mysql.cj.jdbc.Driver");
            // 2.通过DriverManager获取数据库连接
            String url = "jdbc:mysql://localhost:3306/jdbc?serverTimezone=GMT%2B8&useSSL=false";
            String username = "root";
            String password = "2651866367";
            conn = DriverManager.getConnection(url, username,password);

            /**
             * 静态sql语句用Statement
             * 动态sql语句用PreparedStatement
             */
            Scanner sc = new Scanner(System.in);
            System.out.println("请输入你的旧账号名:");
            String n1 = sc.next();
            System.out.println("请输入你的旧密码:");
            String p1 = sc.next();
            System.out.println("请输入你的新账号名:");
            String n2 = sc.next();
            System.out.println("请输入你的新密码:");
            String p2 = sc.next();


            String updateSQL= "update users set name=?,password=? where name=? and password=?";
            PreparedStatement pm = conn.prepareStatement(updateSQL);
            pm.setString(1,n2);
            pm.setString(2,p2);
            pm.setString(3,n1);
            pm.setString(4,p1);
            int res =  pm.executeUpdate();
            if (res>0){
                System.out.println("账号密码更新成功");
            }else {
                System.out.println("账号密码更新失败");
            }

        } catch (ClassNotFoundException e){
            e.printStackTrace();
        } finally {
            // 6.回收数据库资源
            if (rs != null){
                try {
                    rs.close();
                }catch (SQLException e){
                    e.printStackTrace();
                }
                rs = null;
            }
            if (stmt != null){
                try {
                    stmt.close();
                } catch (SQLException e){
                    e.printStackTrace();
                }
                stmt = null;
            }
            if (conn != null){
                try {
                    conn.close();
                } catch (SQLException e){
                    e.printStackTrace();
                }
                conn = null;
            }
        }

    }
}
